This invention relates to a static induction apparatus such as transformer and reactor. More particularly, it relates to an isolator for reducing the amount to which the vibration of the main device of the static induction apparatus appears in the form of noise externally.
With urban developments, ordinary houses have been built near a substation etc., and the reduction of noise from static induction apparatuses which are installed on the substation etc. has been eagerly requested. Especially the noise developing in the iron core of the static induction apparatus is of high energy, and several preventive measure against the noise have heretofore been adopted.
For example, it has been known to surround the static induction apparatus with sound insulation walls by the use of concrete or iron plates. They thus become large-scaled facilities and incur increases in the installation area and the cost. It has also been known to mount a sound insulation panel on the reinforcing channel of the tank side plate of the static induction apparatus through an elastic body of rubber or the like (EPRI Report EL-529 Research Project 579-1, 2-55).
For an effective sound insulation, however, the spring constant of the elastic body supporting the sound insulation panel needs to be made very small.
The diminution of the spring constant is limited because the elastic body must be simultaneously endowed with a strength necessary for supporting the sound insulation panel. It has therefore been difficult to attain a satisfactory sound insulation effect.